Add screen recorder tool

This commit adds a new, built-in screen recorder tool.  The tool UI is
still very simple, start with mod-r and stop it again with mod-r.
The recording is written to capture.wcap, in a simple run-length encoded
adhoc format.  The wcap-decode tool can be used to extract a single frame
from the capture, for now, but the plan is to hook this up to libvpx and
generate webm output.

src/Makefile.am

@@ -1,5 +1,12 @@
 bin_PROGRAMS = weston				\
-	       $(weston_launch)
+	$(weston_launch)			\
+	wcap-decode
+
+wcap_decode_SOURCES =				\
+	wcap-decode.c
+
+wcap_decode_CFLAGS = $(CAIRO_EGL_CFLAGS)
+wcap_decode_LDADD = $(CAIRO_EGL_LIBS)
 
 AM_CPPFLAGS =					\
 	-DDATADIR='"$(datadir)"'		\

src/compositor.c

@@ -1082,6 +1082,8 @@ weston_output_finish_frame(struct weston_output *output, int msecs)
 		wl_display_get_event_loop(compositor->wl_display);
 	int fd;
 
+	wl_signal_emit(&output->frame_signal, &msecs);
+
 	if (output->repaint_needed) {
 		weston_output_repaint(output, msecs);
 		return;
@@ -2530,6 +2532,7 @@ weston_output_init(struct weston_output *output, struct weston_compositor *c,
 	weston_output_move(output, x, y);
 	weston_output_damage(output);
 
+	wl_signal_init(&output->frame_signal);
 	wl_list_init(&output->frame_callback_list);
 	wl_list_init(&output->resource_list);
 

src/compositor.h

@@ -124,6 +124,7 @@ struct weston_output {
 	struct weston_output_zoom zoom;
 	int dirty;
 	struct wl_list read_pixels_list;
+	struct wl_signal frame_signal;
 
 	char *make, *model;
 	uint32_t subpixel;

src/screenshooter.c

@@ -21,8 +21,12 @@
  */
 
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <linux/input.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/uio.h>
 
 #include "compositor.h"
 #include "screenshooter-server-protocol.h"
@@ -206,6 +210,183 @@ screenshooter_binding(struct wl_seat *seat, uint32_t time,
 					screenshooter_exe, screenshooter_sigchld);
 }
 
+struct weston_recorder {
+	struct weston_output *output;
+	uint32_t *frame, *rect;
+	uint32_t total;
+	int fd;
+	struct wl_listener frame_listener;
+};
+
+static uint32_t *
+output_run(uint32_t *p, uint32_t delta, int run)
+{
+	int i;
+
+	while (run > 0) {
+		if (run <= 0xe0) {
+			*p++ = delta | ((run - 1) << 24);
+			break;
+		}
+
+		i = 24 - __builtin_clz(run);
+		*p++ = delta | ((i + 0xe0) << 24);
+		run -= 1 << (7 + i);
+	}
+
+	return p;
+}
+
+static void
+weston_recorder_frame_notify(struct wl_listener *listener, void *data)
+{
+	struct weston_recorder *recorder =
+		container_of(listener, struct weston_recorder, frame_listener);
+	struct weston_output *output = recorder->output;
+	uint32_t msecs = * (uint32_t *) data;
+	pixman_box32_t *r;
+	pixman_region32_t damage;
+	int i, j, k, n, width, height, run, stride;
+	uint32_t delta, prev, *d, *s, *p, next;
+	struct {
+		uint32_t msecs;
+		uint32_t nrects;
+	} header;
+	struct iovec v[2];
+
+	pixman_region32_init(&damage);
+	pixman_region32_intersect(&damage, &recorder->output->region,
+				  &recorder->output->previous_damage);
+
+	r = pixman_region32_rectangles(&damage, &n);
+	if (n == 0)
+		return;
+
+	header.msecs = msecs;
+	header.nrects = n;
+	v[0].iov_base = &header;
+	v[0].iov_len = sizeof header;
+	v[1].iov_base = r;
+	v[1].iov_len = n * sizeof *r;
+	recorder->total += writev(recorder->fd, v, 2);
+	stride = output->current->width;
+
+	for (i = 0; i < n; i++) {
+		width = r[i].x2 - r[i].x1;
+		height = r[i].y2 - r[i].y1;
+		glReadPixels(r[i].x1, output->current->height - r[i].y2,
+			     width, height,
+			     output->compositor->read_format,
+			     GL_UNSIGNED_BYTE, recorder->rect);
+
+		s = recorder->rect;
+		p = recorder->rect;
+		run = prev = 0; /* quiet gcc */
+		for (j = 0; j < height; j++) {
+			d = recorder->frame +
+				stride * (r[i].y2 - j - 1) + r[i].x1;
+			for (k = 0; k < width; k++) {
+				next = *s++;
+				delta = (next - *d) & 0x00ffffff;
+				*d++ = next;
+				if (run == 0 || delta == prev) {
+					run++;
+				} else {
+					p = output_run(p, prev, run);
+					run = 1;
+					prev = delta;
+				}
+			}
+		}
+
+		p = output_run(p, prev, run);
+
+		recorder->total += write(recorder->fd,
+					 recorder->rect,
+					 (p - recorder->rect) * 4);
+
+#if 0
+		fprintf(stderr,
+			"%dx%d at %d,%d rle from %d to %d bytes (%f) total %dM\n",
+			width, height, r[i].x1, r[i].y1,
+			width * height * 4, (int) (p - rect) * 4,
+			(float) (p - rect) / (width * height),
+			total / 1024 / 1024);
+#endif
+	}
+
+	pixman_region32_fini(&damage);
+}
+
+static void
+weston_recorder_create(struct weston_output *output, const char *filename)
+{
+	struct weston_recorder *recorder;
+	int stride, size;
+	struct { uint32_t width, height; } header;
+
+	recorder = malloc(sizeof *recorder);
+	recorder->output = output;
+
+	stride = output->current->width;
+	size = stride * 4 * output->current->height;
+	recorder->frame = malloc(size);
+	recorder->rect = malloc(size);
+	recorder->total = 0;
+	memset(recorder->frame, 0, size);
+
+	recorder->fd = open(filename,
+			    O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0644);
+
+	header.width = output->current->width;
+	header.height = output->current->height;
+	recorder->total += write(recorder->fd, &header, sizeof header);
+
+	recorder->frame_listener.notify = weston_recorder_frame_notify;
+	wl_signal_add(&output->frame_signal, &recorder->frame_listener);
+	weston_output_damage(output);
+}
+
+static void
+weston_recorder_destroy(struct weston_recorder *recorder)
+{
+	wl_list_remove(&recorder->frame_listener.link);
+	close(recorder->fd);
+	free(recorder->frame);
+	free(recorder->rect);
+	free(recorder);
+}
+
+static void
+recorder_binding(struct wl_seat *seat, uint32_t time,
+		 uint32_t key, uint32_t button, uint32_t axis,
+		 int32_t state, void *data)
+{
+	struct weston_seat *ws = (struct weston_seat *) seat;
+	struct weston_compositor *ec = ws->compositor;
+	struct weston_output *output =
+		container_of(ec->output_list.next,
+			     struct weston_output, link);
+	struct wl_listener *listener;
+	struct weston_recorder *recorder;
+	static const char filename[] = "capture.wcap";
+
+	listener = wl_signal_get(&output->frame_signal,
+				 weston_recorder_frame_notify);
+	if (listener) {
+		recorder = container_of(listener, struct weston_recorder,
+					frame_listener);
+
+		fprintf(stderr, "stopping recorder, total file size %dM\n",
+			recorder->total / (1024 * 1024));
+
+		weston_recorder_destroy(recorder);
+	} else {
+		fprintf(stderr, "starting recorder, file %s\n", filename);
+		weston_recorder_create(output, filename);
+	}
+}
+
 static void
 screenshooter_destroy(struct wl_listener *listener, void *data)
 {
@@ -236,6 +417,8 @@ screenshooter_create(struct weston_compositor *ec)
 						shooter, bind_shooter);
 	weston_compositor_add_binding(ec, KEY_S, 0, 0, MODIFIER_SUPER,
 					screenshooter_binding, shooter);
+	weston_compositor_add_binding(ec, KEY_R, 0, 0, MODIFIER_SUPER,
+					recorder_binding, shooter);
 
 	shooter->destroy_listener.notify = screenshooter_destroy;
 	wl_signal_add(&ec->destroy_signal, &shooter->destroy_listener);

src/wcap-decode.c

@@ -0,0 +1,207 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the copyright holders not be used in
+ * advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission.  The copyright holders make
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <sys/mman.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+
+#include <cairo.h>
+
+struct wcap_header {
+	uint32_t width, height;
+};
+
+struct wcap_frame_header {
+	uint32_t msecs;
+	uint32_t nrects;
+};
+
+struct wcap_rectangle {
+	int32_t x1, y1, x2, y2;
+};
+
+struct wcap_decoder {
+	int fd;
+	size_t size;
+	void *map, *p, *end;
+	uint32_t *frame;
+	int width, height;
+};
+
+static void
+wcap_decoder_decode_rectangle(struct wcap_decoder *decoder,
+			      struct wcap_rectangle *rect)
+{
+	uint32_t v, *p = decoder->p, *d;
+	int width = rect->x2 - rect->x1, height = rect->y2 - rect->y1;
+	int x, i, j, k, l, count = width * height;
+	
+	d = decoder->frame + (rect->y2 - 1) * decoder->width;
+	x = rect->x1;
+	i = 0;
+	while (i < count) {
+		v = *p++;
+		l = v >> 24;
+		if (l < 0xe0) {
+			j = l + 1;
+		} else {
+			j = 1 << (l - 0xe0 + 7);
+		}
+
+		for (k = 0; k < j; k++) {
+			d[x] = (d[x] + v) | 0xff000000;
+			x++;
+			if (x == rect->x2) {
+				x = rect->x1;
+				d -= decoder->width;
+			}
+		}
+		i += j;
+	}
+
+	if (i != count)
+		printf("rle encoding longer than expected (%d expected %d)\n",
+		       i, count);
+
+	decoder->p = p;
+}
+
+static int
+wcap_decoder_get_frame(struct wcap_decoder *decoder)
+{
+	struct wcap_rectangle *rects;
+	struct wcap_frame_header *header;
+	uint32_t *s;
+	uint32_t i;
+	int width, height;
+
+	if (decoder->p == decoder->end)
+		return 0;
+
+	header = decoder->p;
+
+	rects = (void *) (header + 1);
+	decoder->p = (uint32_t *) (rects + header->nrects);
+	for (i = 0; i < header->nrects; i++) {
+		width = rects[i].x2 - rects[i].x1;
+		height = rects[i].y2 - rects[i].y1;
+		wcap_decoder_decode_rectangle(decoder, &rects[i]);
+	}
+
+	return 1;
+}
+
+struct wcap_decoder *
+wcap_decoder_create(const char *filename)
+{
+	struct wcap_decoder *decoder;
+	struct wcap_header *header;
+	int frame_size;
+	struct stat buf;
+
+	decoder = malloc(sizeof *decoder);
+	if (decoder == NULL)
+		return NULL;
+
+	decoder->fd = open(filename, O_RDONLY);
+	if (decoder->fd == -1)
+		return NULL;
+
+	fstat(decoder->fd, &buf);
+	decoder->size = buf.st_size;
+	decoder->map = mmap(NULL, decoder->size,
+			    PROT_READ, MAP_PRIVATE, decoder->fd, 0);
+		
+	header = decoder->map;
+	decoder->width = header->width;
+	decoder->height = header->height;
+	decoder->p = header + 1;
+	decoder->end = decoder->map + decoder->size;
+
+	frame_size = header->width * header->height * 4;
+	decoder->frame = malloc(frame_size);
+	memset(decoder->frame, 0, frame_size);
+
+	return decoder;
+}
+
+void
+wcap_decoder_destroy(struct wcap_decoder *decoder)
+{
+	munmap(decoder->map, decoder->size);
+	free(decoder->frame);
+	free(decoder);
+}
+
+static void
+write_png(struct wcap_decoder *decoder, const char *filename)
+{
+	cairo_surface_t *surface;
+
+	surface = cairo_image_surface_create_for_data((unsigned char *) decoder->frame,
+						      CAIRO_FORMAT_ARGB32,
+						      decoder->width,
+						      decoder->height,
+						      decoder->width * 4);
+	cairo_surface_write_to_png(surface, filename);
+	cairo_surface_destroy(surface);
+}
+
+int main(int argc, char *argv[])
+{
+	struct wcap_decoder *decoder;
+	int i, output_frame;
+	char filename[200];
+
+	if (argc != 2 && argc != 3) {
+		fprintf(stderr, "usage: wcap-decode WCAP_FILE [FRAME]\n");
+		return 1;
+	}			
+
+	decoder = wcap_decoder_create(argv[1]);
+	output_frame = -1;
+	if (argc == 3)
+		output_frame = strtol(argv[2], NULL, 0);
+
+	i = 0;
+	while (wcap_decoder_get_frame(decoder)) {
+		if (i == output_frame) {
+			snprintf(filename, sizeof filename,
+				 "wcap-frame-%d.png", i);
+			write_png(decoder, filename);
+			printf("wrote %s\n", filename);
+		}
+		i++;
+	}
+
+	printf("wcap file: size %dx%d, %d frames\n",
+	       decoder->width, decoder->height, i);
+
+	wcap_decoder_destroy(decoder);
+}